raymond



(No Mode1.)iv 6 Sheets-She I.

REDUGINGMAGHINE. 2 No. 387,539. PatenteAugg 88 "D I l L l"llllllllllllllll lli - i REDUCING MACHINE.

IlllllllflfllllllllUliIlIlIIIIlIlIIlIIIlIUINHUIIIIHIHIINUNI www s snee ttttttttt Patented Aug. 7, 1888.

6 Sheets-Sheet 3.

(No1/Lodel.) f l G. 8u A. RAYMOND.

REDUGING MACHINE.

Patented Aug. 7, 1888.A

E; lill." l 'su l (N0 MOdeL) 6 Sheets-Sheet 4.

G. 88 A. RAYMOND.

RBDUGING MACHINE.'

No. 887,539. Patented' Aug. 7, 1888.

NA PETERS, Pmmmhognpher. wgshnmn, D. C,

(No Model.) 6 Sheets-Sheet 5.

- G. au A. RAYMOND.

RBDUGING MACHINE.

No. 387,539. Patented Aug. 7, 1888.

lllllllllllllllilllllllh u8 a il o 6 Sheetsf-Sheet 6.

(No Model.)

e. an A. RAYMOND.

-REDUGING MACHINE. No. 387-;539. Patented Aug. "7, 1888.

GEORGE RAYMOND AND ALBERT RAYMOND, OF CHICAGO, ILLlNOlS, ASSIGN- FFE@ ORS TO THE CYCLONE PULVERIZER COMPANY OF THE UNITED STATES or AMERICA, or New YORK, N. Y.

REDUCING SPECIFICATION forming part of Letters Patent No. 387,539, dated August 7, 1888.

Application filed December 30. 1886. Serial No. 223.026. (No model.) Patented in England January QG, 1F87, No. 1,270.

To all whom it 77mg/ concern:

Be it known that we, GEORGE RAYMOND and ALBERT RAYMOND, of Chicago, Illinois, have invented certain new and useful Improvements 5 in educing-li/lachines, (for which we have obtained a patent in Great Britain, No. 1,270, bearing date January 26, 1887,) which we desire to protect by Letters Patent of the United Stat es, and of which the following is a specilication.

Our invention relates to machines for reducing ores and other materials by impact and attrition between the fragments; and our inveution consists in certain novel features of construction, whereby the working of such machines is greatly improved, as hereinafter described and claimed.

In the drawings annexed, forming a part of this specification, Figure 1 is a side elevation of our improved reducing-machine, a part of the top being represented as broken ofi and shown on the left hand of the main part of the ligure. Fig. 2 is a plan View, partly in section, through line 2 2, Fig. 1. Fig. 3 is an end view ol' the reducing-machine as it appears when viewed from the position indicated by arrow 3, Fig. il. Fig. 4 is a central vertical cross-section of thc machine. Fig. 5 is a side elevation of the rcducinganachine,withits central portion in vertical axial section. Fig. 6 represc nts the separati ngfchamberas it appears when seen from the side opposite to that shown in Fig. 1. Fig. 7 is aside View of the same. Figs. 8, 9, and Il() are details on an enlarged scale, and Figs. 11, 12, 13, and 14 are details on the saine scale as the'other parts of the ma chine. Fig. 15 represents the machine when set up for operation, in connection with a number of auxiliary devices used in putting our invention into practice, a portion of the righthand lower corner of said figure being in cross-section. Fig. 16 is a central vertical scction on line 1G 1 6, Fig. 15, on reduced scale.

The general appearance of our improved machine is similar to those patented to us in Letters Patent of the United States, Nos. 293,786 and 293,787, dated February 19, 1884, and is constructed as follows:

Upon two main shafts, 1 and 2, mounted in suitable bearings and driven from pulleys and 4, or by means of other connecgiven to the beaters.

tion with a motive power, are mounted, within the pulverizngchamber 5, hubs 6 and 7, from which project arms 8, carrying beaters 9. These arms S, circular in cross section, are bent to the shape of the beat ers, and the direction of their bent portion is determined by the inclination desired to be Preferably these arms are made in one piece with the hub and of caststeel; but they may be set into a separatelycast hub, as indicated bythe broken lilies extending into the hub in Fig. 4. They are made comparatively large near the hub, their large portion being reduced so as to form shoulders, against which the beaters bear when attached.

Each beater 9 is channeled, so as to receive the arms 8, and is attached thereto by a bolt, 10, passing through the beater and its respective arm and there fastened by a nut, and also by a clip, 11, embracing the arm, passing on both sides of the same through the beater, and there secured by nuts, as will be clearly seen by reference to Figs. 4 and 5. The beaters are herein shown flat for convenience, and in such form are serviceable; but we prefer the spiral or screw-shaped form shown in our previous This construction enables us to changethe beaters when they become worn patents.

without disturbing or replacing the hub, and

likewise enables us to replace the beaters with others of different shape if for any reason this becomes desirable. This construction, moreover, is cheap, strong, and du rablc.

Ribs 12,

Fig. 5, are formed on the beaters, one on each side of the channel, to more securely grasp the arm; but a plain groove or channel may be used, if preferred.

The casing of the pulvcri'lzing -chamber is side pieces, 19 and 20.

shown.

These several pieces are flanged and ground, so as to fit each other at the joints, and are bolted together, as For convenience it is desirable that one ofthe side pieces, as 20, should be hinged,

of the pulvcrizing chamber.

as shown in dotted lines, Figs. 3, 4, and 5, so that when its securingbolts are removed it may be opened to permit access to the interior A handle, 2l,

IOO

Fig. 3, is provided for conveniently pulling out this hinged side. Two currents of air are delivered to opposite ends, respectively,of the pulverizing-ehamber, pipes 22 and 23, Fig. 1, being provided for that purpose and forming part of the end and side pieces of the easing. These pipes project toward the same side of the machine, for convenience iu attaching pipes thereto, and pass down to diagonallyopposite parts of the pulverizing-chamber near its bottom.

It is desirable that the air should enter at the bottom of the chamber, in order that the beaters and the material operated upon may be between the air as it enters and the pas sage-way, through which it leaves the chamber, since were the air-pipes otherwise located the air would be too readily and quickly drawn out from the chamber. It is desirable that they should enter at diagonallyopposite parts of the chamber, in order that the beaters, which revolve in opposite directions, may receive the air as they pass down and, sweeping it along the bottom of the chamber, give it the most perfect rotary motion possible.

Instead of making the chamber simply double-cone shaped, as heretofore, we propose to introduce a modifica-tion which enables us to more readily adapt the machine to grinding with dilTerent degrees of iineness, and this modication consists in an annular extension, 24, of the pnlverizing-chamber surrounding the latter at its center. The width of this annnlar extension is approximately equal to the width ofthe clear space between the free ends of the two sels of beaters within the reducingchamber, as will hereinafter more fully appear. This annular spaceis adapted to be put into communication with it by means of the spaces between grate-bars 25, Fig. 9, or to be eut eilj i'rom it entirely by solid segmental pieces 26, it being understood that the gratebars are taken out and the solid segmental pieces put in their places when it is desired to cut the annular extension 21 off from the pulveriziiig-chamber. These grate-bars or segmental pieces are held in position between the edges of two annularstrips of lining, pref` erably of chilled metal, placed about the interior cone-shaped surfaces of the pulverizingchamber. This lining is in part shown in Figs. 2, 4, and 13, and is made, preferably, in eight parts, two parts, 13 14., Fig. 5, fitting into and corresponding with the interior coneshaped surface of the bottom piece of the casting 15, four parts, two of which, 27 23, are shown in Fig. 5, corresponding to and fitting the interior curved surfaces of the side top pieces of casing 19 and 20, each of these parts being provided, Fig. 13, with an upwardlyextending ilange, 31, lying along the inner face of one of the sides of the upwardly-projecting discharge-openiugs 32, and two parts, 33 and 34, spanning the gap between the parts 27 and 2S, and the other two similar parts (not showin) respectively j ust above the annular extension 2-1. These parts 33 and 34 are attaehed by bolts passing through slots 29, so that they maybe pressed down with greater or less firmness upon the gratebars, (or solid segments, when the latter are in place,) and may be readily removed when it is desired to replace the gratebars by the segments, or vice versa.

The gratebars and segments are made of the shape shown, so as to accurately [it the space left between the adjoining edges of the annular strips of lining and to be held therein, and are inserted, preferably, from the top, one of the readily-removable pieces of lining, 33 or 34, having been taken out for that purpose. These grate-bars are each provided with lugs 35, 36, and 37, Fig. 9, one at each end and one at the center, for holding them at proper distances from each other. The lower edges of' the adjustable plates 33 and 34 are beveled, as shown in Fig. 4, so as to give them a bearing upon the bars or segments. r1`he object of these grate-bars and ofthe annular extension 2-1 will now be explained.

'When it is desired to pulverize to a considerable degree of iineuess, the segmental plates are used, completely cutting olf the annular extension 24 from the pulveriziiig-chamber proper; but when it is only desired to comminute the material operated upon to a moderate degree, thegrate-bars are inserted, and as fast as the material is reduced sufficiently to pass through the opening between them it enters the chamber 2-1 and is permitted lo pass out through the bottom discharge-opening, 16. During the operation of the machine for fine grinding this opening 16 is closed, and all the material passes up in the form ofdust through the top passage-way, Vfhen, however, the comminution is moderate, the air-current is not depended upon to carry off the ground product; but it drops down, as stated, by gravity, passing through the grate-bars and out through the opening 1G.

The degree of comminntion effected by the machine is determined, when the grate-bars are used, by the width of the spaces between them, and a complete machine should be provided with a number oi' sets of bars adapted to various degrees of comminution. XVe find ICO it desirable to use the suction-fan and the entire air-passage attachment when the machine is doing coarse work as well as when it is doing (ine work. In the former case the increased air-pressure duc to the i'an assists in holding the material being operated upon up from the bottom of the pulverizing-chamber and between the beaters, where it is most rapidly attacked, and thus very materiallyincreases the capacity of the machine. Then so used the material should be allowed to drop into a closed box. The use of the air-blast with the screen has the further advantage that such line dust as is formed is carried oil' to the settlingchambers instead of being mingled with the coarser product, as would otherwise be the case, which is also a distinctive advantage.

It will of course be understood that we do scrisse 3 not limit ourselves to the use of the machine for coarse grinding with the air-blast, as useful results, though in a minor degree, are obtainable without the air-blast.

When it is desired to change the machine from a condition adapted to coarse grinding to4 one adapted to tine grinding, instead of replacing the grate-bars by the segmental plates discharge-opening 16 may be merely blocked up, and the annular extension 24 allowedto till with dust or more or less comminuted particles, which it will speedily do, until the spaces between the grate-bars and the sides of the annular extension are thoroughly packed. The pulverizer will new operate forline grinding precisely as it would if the annular exten-` sion 24 were leut oft' by. the segmental plates, the only disadvantages being the retention in the machine of the material filling the annular extension and the liability of the new material worked upon to become more or less mixed with the old remaining in the machine, which, according to circumstances, may or may not be a disadvantage.

Formed as an upward extension or continuation ofthe top passage-way, 32, is a separating-chamber, 38, its top curved, as shown in Fig. 6,by appropriate sh'ading,and in Fig. 7 in elevation, and provided withadischarge-pipe, 39. rDhis separating-chamber is made comparatively large, so that the air and pulverized material will have an opportunity to eirculate freely about in it, that the coarser portion may fallback into the ehamber,while only the iiner passes out through the dischargepipe 39. To assist this action of the separating-chamber, I provide a partition, 40, Fig. 7, placed near the entrance tothe discharge-pipe 39, so that the material as it passes up into the separating-chamber will be forced by the configuration of the top of the latter to pass through the partition and take a downward direction, whereupon the coarser parts of such material will fall and return under the partij tion, as indicated by the arrow, into the pulveriziug-chamber, while the finer portion will be drawn out by the ai r-current through the pipo 39. l

lt will be noticed that the size of the top discharge-opening, 32, is very much larger relatively to the p ulverizi iig-chamber than that shown in our former patents, said dischargeopening in this machine beingin cross-section practically of the same length as the pulverizing-chamber and nearly two-thirds of its width, and we find by experiment that atop discharge-opening of approximately the relative size shown gives far better results than are obtained where it is considerably smaller. It appears that the material in the pulverizingchamber, having attained a rapid rotary motion, is driven past the dischargeopening when the latter is relatively small without entering it, while when the opening is sutiiciently large it is drawn up into it and out. It would also appear that the increased length of the discharge-opening affords an opportunity for the imperfectly-pulveriZed material to fall upon the upper portions of theinclined plates 13 14, and thus to receive the full een` trifugal impulse of the beaters before passing again to the point where the reduction takes place.

We have found that good results are obtained when the upward opening is even as large as the maximum cross-section of the pulverizing-chamber; but the relative size of the opening shown is more convenient and gives equally good, and perhaps somewhat better, results. The large opening, when used in connection with the separating-chamber, also permits the upward current of air charged with the material under treatment in a more or `less pulverized condition to circulate freely, and to some extent to return upon itself without passing over the screen, so that the coarser particles fallback directly into the pulverizingchamber. We suppose that there are two continuous streams ofthe coarser material diverging from the center of the pulverizing and the separating chambers, curving over sidewise and passing down the end walls to the beaters, as indicated in Fig. 5. These currents carry back the coarse materials to be *further comminuted. This is impossible where the separating-chamber, or the opening between it and the pulveriziiig-chamber, is of relatively small dimensions. On the contrary, the coarse particles are effectually prevented in this case from returning by the pressure in the narrow throat,and some such device as the automaticvalve arrangement of our former patents is necessitated, which, however, is not satisfactory in operation. The material to be pnlverized is introduced through a hopper, 4l., placed on one side of chamber 3S, its opening being near the bottom ofthe latter. The feed of the material is insured and regulated by a bladed roller, 42, journaled in the hopperand intermittently rotated bya shaft, 43, journaled in the bearings 44 45, attached to the outside of the separating-chamber, the shaft 43 being connected by bevel-gearing with the shaft of the bladed feed-roller and having on its other extremity a pawl-and-ratchet connection with a rod, 46, eccentric-ally pivoted at its upper end to a pulley, 47, geared to any suitable source of motive power. rlhe pawl andratchet connection referred to consists of a ratchet-wheel, 48, rigidly attached to the shalt 43, and an arm, 49, pivoted thereon and carrying a pawl, 50, the other end of arm 49 being connected with rod 46 by a pin, 5l,-a number of holes being provided in the end ot' arm 49 for this pin, whereby the amount of motion of the pawl 5() may be regulated so as to give a more or less extensive rotary motion to the feed-rolleron each rcciprocation of the arm 49, and thus the raw material is pushed into the pulverizingchamber more or less rapidly. rlhis pawl-and-rateliet movement is more readily adjusted and ou the whole more convenient thana gearing-down connection between the source of power and the feed-roller, though IOO ITS

such a connection might be used. The mateY rial is prevented from falling freely into the pulvcrizingehamher by a movable bottom, 52, pivoted in the hopper at 53, and provided with a counterbalance-weight, 54, rigidly attached to it, the movable bottom resting against iheblades of thc feed-roller or bearing on other bearing-surfaces or shoulders l'ornicd on the sides of the hopper. Thisbottom is forced down by the blades of the feedwheel, as the latter drives on the coarse material, sufficiently to permit a proper feed.

llcaturcs of our improved machine to which we desire to call attention are the absolute distance between the contiguous faces of the oppositely-revolving beaters and also that distance' relative to the total length of the machine. 'We find that increase of the space be tween the beaters tends to increase the fixiencss of the resulting product. The best average results are obtained with a space which bears the proportion of one to three to the total length of the pulverizing'chamber, and which with machines of ordinary size is about ten to twelve inches. \\fhilc, however, thc proportion above indicated of one to three is that which we believe to be the best, yet, if the absolute distance of ten to twelve inches between the beaters be preserved the relative length of the chamber may be varied considerably without very greatly affecting the operation ofthe machine. It appears, therefore, that the absolute distance between the beaters of more importance than that distance relative to the length ofthe chamber. If this space is narrower the machine will do less work. The difference is probably due to the fact that the rapid rotation of the beaters pro duees a partial central vacuum within and between they heaters, toward which the air and the material under treatment rush in around the beaters and through the clear space between them. Il' this space is narrow the material is prevented from free access to the central vacuum space and the work done by the machine is below its maximum capacity; but when the space between the sets of beaters is large enough to permit free movement of the material as it is drawn toward the central vacuum the maximum capacity of the machine will be attained. This broad space also permits the formation ofeddying cnrrents,the tendency of which is to further comminute the material.

there the machine is used for coarse grinding, we find it desirable to introduce oblique guide-snrfauzes 74 (shown in broken lines in Figs. l and 5 and in full shading linesin Fig. fl) to protect the shaft, hubs, and arms of the heaters from the impact of the falling fragments, since if they are permittul to strike those paris they rapidly wear them away. These inclined surfaces it are formed bythe use of blocks. (Illustrated in section in Fig. ll.) Where the grinding is fine it is better to allow the descending dust to pass into the current of air driven forward by the beaters, as above explained, dispensing with the converging guide-surfaces.

Besides the improvements in the construction of the pulverizer itself herein described we have made improvements in the method of using the machine, which will now be de scribed. W'here fresh air is continually drawn into the pulverizer andthe air which has been separated from the dust formed by itis allowed to escape freely, there will always be more or less waste of material carried out from the machine by the escaping air, and the operation of the machine will be more or less irregular, owing to variations in the supply of air to the machine.

We propose to continuously use practically the same body of air with the machine, freeing it more or less perfectly from dust after it passes out of the pnlverizing-chamber, and then drawing it back into the pnlverizingchamber for further use. \Ve thus avoid all waste of the material operated upon, and we also obtain a constant and uniform quantity of airin the machine and its connections. After leaving the machine and passing through the dischargepipe 39,the air enters a series of settling-drums, 56, provided prefcrabl y with partitions of usual construction,57 58, for checking the airfcurrent and connected by discharge-pipes 59 and (llprovidcd with weighted valves 75 and 7G, with runway 61 through which the dust is forced by ascrew conveyer, 62, to a discharge-pipe, 63, entrance to which is controlled by a weighted valve, 64;. From the last settling-drum 56 the air passes through a pipe, 65, to a suction-fan, (36, whence it is delivered into another settlingchamber, 67, provided with partitions 68 and connected at its other end by the pipe G9 with the air-pipe 22 23 of the pulverizer. The top of this set tlingchamber (57 is formed of a considerable length of tolerably close canvas stretched over a framework formed of two sets of parallel strips, 70 and 71, arranged alternately with respect to each other and some little distance apart, so that the air in the settlingchamber 67 has free access to all parts of the canvas except such as are in immediate contact with the strips. rllhis canvas acts as an equalizing-valve with respect to the air in the system of pipes and chambers, permitting air to slowly enter when too little is in the sys tem and to slowly pass out when too much has been drawn in, and at the same time arresting any dust which would otherwise pass out with the air. For further regulating the suction of the fan G6 upon the settling-chambers 55 and 56 avalve, 72, is provided in pipe 65, and to regulate the suction of the beaters in the pulverizing-chamber upon the air in the settling chamber 67 a valvc,73,is provided in pipe 69.

A further advantage of the cqualiziugvalve is that it prevents an overcharge of air in the machine from forcing dust out through cracks and crevices in any part of the machine into the outer airan inconvenience which is often attendant upon the use of reducing-machines IIO and is often highly detrimental tothe health of the operators. To enable the operation of the equalizing -valve to be thoroughly understood, it may be necessary to go somewhat more into detail in the explanation of the principle of its operation. Let us suppose, iirst, that the pulverizer is used without the exhaust-fan and without the returning airpipe, air being simply drawn into the pulverizing-chamber through the end holes provided in the machine formerly patented to us, and allowed to escape into the outer air after passing through the settling-drums. [n this case the beaters, operating as fans to produce a strong draft, force the air in a powerful current up through the separating-chamber and giving it a tendency to escape whenever there may be an imperfect joint or a gap in the walls of any part of the machine. As the dust is exceedingly line, and it is practically impossible to make a machine absolutely impervious at all points to it, it is found that more or less dust is usually given oli' into the room in which the machine is situated,with its attendant inconveniences and dangers. New if, to a machine so placed, an exhaustfan is applied on the farther side of the settlingchambers, the tendency of the dust to escape from the machine itself will be reduced, as all the pulverized material will be given agreatlyincreased tendency to pass up through the discharge openings and pipes and into the settling-chamber; but at the same time a greater amount of the material will be drawn through the settling-chambers, pass into the outer air, and be wasted. If, now, in order to prevent this waste, the air-pipe is extended from the exhaust-fan back to the pulverizing-maehine without an equalizingvalve, the difficulty experienced in the rst case supposed is again it'elt,but in an exaggerated degree,for one of two conditions must exist-either `the entire system of air-passageway chamber is altogether air-tight and the amount of air contained in it therefore absolutely constant, or, as is much more probable,` there are a number of opportunities in various parts of the machine and connections for air to pass in and out. Such opportunities are in fact necessary if the machine is to be run at varying speeds or with widely-different kinds of material, that the quantity of air used may be adapted both to the speed of the machine and the character of the material undergoing treatment. If such opportunities for the egress and ingress of air exist they are apt to be irregular and uncertain in their action, giving at times a surplus and at times a deiicit of air. Under both conditions the machine will operate with less than its normal capacity and eii'ectiveness, both as to quantity and quality of work done, and where there is an excess of air there will be even a greater tendency to force the iiner dust out into the air about the machine than is observed where no exhaustfan is used. rlhe equalizingvalve, however, overcomes both these difficulties by causing the machine to automatically regulate, in a steady and reliable manner, its supply of air in accordance with its varying requirements, and altogether preventing the tendency referred to-to force out the finer dust from the machine. While other relative positions of the equalizingvalve and the exhaust-fan might perhaps be devised, it is obvious that the position shown-viz., that wherein the equalizing-valve stands in the return-pipe between the fan and the pulverizingchamber-has advantages in that, iirst, it throws the suction of the fan to the fullest extent upon the pulverizing-chamber, and, second, enables the action of the equaliZing-valve to be felt directly at the entrance to the pulverizing-chamber, where it will be most directly and immediately effective upon and governed by the operating parts of the machine. Many other forms of this equalizing-valve might undoubtedly be readily devised.

Having thus described our invention, what we claim, and desire to protect by Letters Patent of the United States, is-

1. In a reducing-machine, the combination of a circular chamber, two sets of beaters placed one in each end of said chamber, and means for causing said beaters to revolve, the said beaters having between their inner revolving edges a clear space of a width equal approximately to one-third the length of the chamber, and the said chamber being provided with au upward discharge-opening substantially equal in length to the length of the chamber, substantially as described.

2. In a reducing-machine, the combination of a circular elongated pulverizing-chamber, two sets of beaters, one placed in each end, said beaters having a clear space between their revolving faces, means for causing said beaters to revolve, said chamber having an upward discharge opening approximately equal in length 'to the chamber itself, and a separatingchamber forming an upward continuation of said discharge opening, substantially as described.

3. In a reducing-machine, the combination of a circular elongated chamber, beaters placed therein, means for causing said beaters to revolve, said chamber being provided with an upward dischargeopening, aseparating-chamber, a discharge-pipe therefrom,and a partial partition located in said separatingchamber between the said upward opening from the chamber containing the beaters and the entrance to the said discharge-pipe,substantially as described.

4. In a reducing-machine, the combination of a pulverizing chamber, rotatable beaters mounted therein, a separating-chamber connected therewith and having a curved top and a discharge-pipe leading from a point below the top of said separating`chamber,and a partition located within the separating chamber in front of the discharge-orifice and above the bottom of the separating-chamber, substantially as described.

5. In a reducing-machine, the combination IOO SiO

of a circular chamber having a larger diame ter at its center than at its ends, two sets of heaters arranged one in each end of said chamber, and means for causing said beaters to revolve, said circular chamber having an upward disehargeopening of approximately the length of the chamber itself and of a width approximately equal to twothirds ol'its largest diameter, substantially as described.

G. In a reducing-maehine, the combination of a circular chamber having a larger diameter at its center than at its ends and provided with an upward discharge-opening, two sets of opposite] y-revol vi n g beaters, one set placed in each end of said chamber, means for causing said beaters to revolve, and two airpipes leading into said circular chamber at its base, one at each end thereof and on opposite sides of the axes of the shafts with respect to each other, substantially as described.

7. In areducingmachine, the combination of a circular elongated pulveriZing-ehamber, two sets of beaters placed one in each end of said chamber, means for causing said beaters to revolve, and two air-pipes approaching the chamber from the saine side and entering the chamber one at each end, with a downward turn and on opposite sides ofthe longitudinal axis thereof, substantially as described.

S. In a reducingmachine, the combination of a circular elongated chamber having a larger diameter at its center than at its ends, two sets of beaters, one placed in each end, means for causing said beaters to revolve,said circular chamber being provided with an npward discharge-opening substantially equal in length to the chamber itself, and guide-blocks attached one to each end wall of the said upward discharge-opening, extending upwardly and inclined outwardly, whereby partiallypulverized material, returning by gravity to the disehargeopening, is detlected toward the center of the same, substantially as described.

9. In a reducing-machine, the combination of an elongated circular chamber, 5, provided with central annular circumferential chamber, 24, removable gratebars 25, placed between said chambers, and adjustable lining-plates 33 and 34, substantially as described.

10. In a reducingmachine, the combination of a pulverizingchamber having a wide ceutral upward discharge-opening and rotatable beaters mounted therein, with a separatingchamber placed over the disellarge-opening and extending beyond the two lateral sides ol' the same,delleetingplates cxt-endingcach from one side of the discharge-opening to the corresponding side of thc separatingchamber, and a dischargepipe from the separating chamber, substantially as described.

11. In a reducingmaehine,the combination of a pulveriziug'ehamber having a central upward dischargeopening and rotatable beaters mounted therein, and a separatiiig-chamber placed over the opening and extending beyond the two sides of the same, closed at its upper end by a curved top, with defleeting-plates extending from the lateral edges of the discharge-opening to the corresponding walls of the separating-chamber, a d ischarge-pipe communicating with one side of the separatingchamber, and a partition within the separating-chamber in front of the opening to the discharge-pipe, substantially as described.

l2. In a reducing-machine, the combination of a pulverizingchamber having a central upward discharge-opening, and a separating chamber extending beyond the two sides of the opening, and rotatable beaters mounted therein placed upon the same,witl1 a dischargepipe extending from one side of the reducingcham ber, and a partition before the entrance of the discharge-pipe and to one side of the discharge-opening, leaving a free space above its upper edge for the passage of the reduced material to the discharge-pipe and a free space below its lower edge for the return of coarse particles to the discharge-opening, substantially as described.

GEORGE RAYMOND. ALBERT RAYMOND. Witnesses:

FREDERICK C. GOODWIN, E. L. HUBER. 

